Both the CDC and the AAP recommend masking in schools
The CDC and the American Academy of Pediatrics (AAP) recommend that all students, educators, and staff wear masks in school, whether vaccinated or not.
The CDC’s guidance is based in large part on the possibility that even vaccinated people can transmit disease to others. Wearing a mask helps protect those not able or not yet eligible to be vaccinated.
The AAP’s rationale: if everyone has to wear masks, teachers and administrators don’t have to keep track of who is vaccinated and who isn’t, lessening the burden on school staff.